The present invention relates to an extension frame for a transport box or a pallet.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
Transport boxes of plastic with pallet bases have been used for the transport of large workpieces. Examples of such transport boxes are disclosed in a brochure by Georg Utz AG, 5620 Bremgarten, Switzerland. US 2004/0200833 discloses a transport box which can be stacked and collapsed. To prevent the sidewalls of such transport boxes from twisting, it is desired to distribute the load evenly upon the corner regions. For that purpose, the corner regions are provided with tubular support pillars to stabilize the shape of the transport box. Transport boxes can be increased in height through use of an extension frame to enlarge the load volume. The extension frame includes two opposite long sides and split transverse sides arranged between the long sides and collapsible. Conventional extension frames may bulge when mounted onto a transport box, thereby adversely affecting the overall stability. In addition, even though conventional extension frames are collapsible, their own weight may cause the extension frames to spontaneously open up again. This is very inconvenient when loading or unloading the frame.
It would therefore be desirable and advantageous to provide an improved extension frame to obviate prior art shortcomings.